Dimensional deviation after mold silicone reproduction is an issue many customers are concerned about. Dimensional deviation may originate from multiple aspects including material shrinkage, master pattern precision, mold design, curing conditions, and measurement methods, and cannot simply be attributed to a single factor. Accurately identifying the source of deviation helps optimize the reproduction process.

Mold silicone typically undergoes a certain degree of shrinkage during curing. Addition-cure mold silicone generally has a low shrinkage rate and good dimensional stability, making it suitable for reproduction applications with high precision requirements. Condensation-cure mold silicone is lower in cost and highly versatile, but its dimensional stability may be affected in thick molds or when environmental conditions vary significantly. Shrinkage performance differs among grades, and specific product technical documentation should be taken as the basis.

Master pattern precision directly affects mold dimensions. If the master pattern itself has deformation, machining errors, or 3D printing layer lines, the reproduced product will also inherit these deviations. For high-precision products, it is recommended to first confirm master pattern dimensional stability and measure in a constant-temperature environment. Mold design also affects dimensional performance—for example, uneven wall thickness, insufficient support, or unreasonable parting design can all lead to deformation after demolding.

Curing conditions are equally important. Excessively low curing temperature may lead to incomplete internal curing, with continued shrinkage after demolding; excessively high curing temperature may shorten working time and increase internal stress. For large-volume molds, if the amount of compound poured at one time is too large, significant internal exotherm may also affect dimensional stability. Measurement should be conducted after the mold has fully cured and returned to room temperature, avoiding measurement during significant temperature changes.

If dimensional deviation is found, it is recommended to troubleshoot item by item in the order of "master pattern—mold design—material shrinkage—curing conditions—measurement method." Our company provides mold silicone with different shrinkage rates and precision grades. Customers can select suitable grades based on product precision requirements and verify actual dimensional performance through trial molding.

More information, please click here.